Mitochondrial dysfunction and neurological disorders: A narrative review and treatment overview

Heat-shock chaperone HSPB1 mitigates poly-glycine-induced neurodegeneration via restoration of autophagic flux

The CGG repeat expansions in the 5'-UTR regions of certain genes have been implicated in various neurodegenerative and muscular disorders. However, the underlying pathogenic mechanisms are not well understood. In this study, we explore the role of the small molecular chaperone HSPB1 in counteracting neurodegeneration induced by poly-glycine (poly-G) aggregates. Employing a reporter system, we demonstrate that CGG repeat expansions within the 5'-UTR of the GIPC1 gene produce poly-G proteins, by repeat-associated non-AUG (RAN) translation. Through proximity labeling and subsequent mass spectrometry analysis, we characterize the composition of poly-G insoluble aggregates and reveal that these aggregates sequester key macroautophagy/autophagy receptors, SQSTM1/p62 and TOLLIP. This sequestration disrupts MAP1LC3/LC3 recruitment and impairs autophagosome formation, thereby compromising the autophagic pathway. Importantly, we show that HSPB1 facilitates the dissociation of these receptors from poly-G aggregates and consequently restores autophagic function. Overexpressing HSPB1 alleviates poly-G-induced neurodegeneration in mouse models. Taken together, these findings highlight a mechanistic basis for the neuroprotective effects of HSPB1 and suggest its potential as a therapeutic target in treating poly-G-associated neurodegenerative diseases.Abbreviations: AD: Alzheimer disease; AIF1/Iba1: allograft inflammatory factor 1; Baf A1: bafilomycin A1; BFP: blue fluorescent protein; CQ: chloroquine; EIF2A/eIF-2α: eukaryotic translation initiation factor 2A; FRAP: fluorescence recovery after photobleaching; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFAP: glial fibrillary acidic protein; GFP: green fluorescent protein; HSPB1: heat shock protein family B (small) member 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; NOTCH2NLC: notch 2 N-terminal like C; PD: Parkinson disease; PFA: paraformaldehyde; poly-A: poly-alanine; poly-G: poly-glycine; poly-R: poly-arginine; RAN translation: repeat-associated non-AUG translation; RBFOX3/NeuN: RNA binding fox-1 homolog 3; STED: stimulated emission depletion; TARDBP/TDP-43: TAR DNA binding protein; TG: thapsigargin; TOLLIP: toll interacting protein.

Discovery of Novel 2-Oxindoles as Compounds with Antiglaucoma Activity

Oxindole-based natural indoles analogues retain the rigidity and size of the original indole ring system whilst introducing more 3-dimensionality and potential increased water solubility. We report the first preparation of a diverse series of new melatonin analogues 4, 6, 11, 12 based on 3-hydroxy-2-oxindoles (11) and hydroxy-free 2-oxindoles (4, 6, 12) and evaluated their ability to reduce intraocular pressure as well as their neuroprotective and antioxidant properties. Reductive amination was used to obtain new 5-(benzylamino)-substituted (indolin-3-yl)acetonitriles 11 and (indolin-3-yl)acetic acids 12 with high yields. Compounds 4 a, c, 6 a and 11 a, d, h, j-l demonstrated IOP reduction effect in range 15-27 % similar to the effect of reference compounds melatonin and timolol (12 % and 18 % reduction, respectively). 5-(Benzylamino)-substituted 3-hydroxy-2-oxindoles 11, unlike compounds 4, 6, inhibited lipid peroxidation in range 2.075-13.012 μM. Inhibition of NQO2 associated with antioxidant properties of melatonin was also evaluated for synthesized compounds and it was found that compound 11 h showed the best NQO2 inhibitory activity with an IC50=39 μM (vs. melatonin IC50=64 μM). All synthesized compounds 4, 6, 11, 12 at a concentration of 30 μM do not possess the mitochondrial toxicity. Moreover, no disruption of tubulin polymerization was observed even in the presence of 100 μM of the compounds. Thus, 3-hydroxy-2-oxindole derivatives 11 can be used for drug design of first-in-class antiglaucoma drugs with antioxidant and neuroprotective properties.

Investigating the neuroprotective effects of polyunsaturated fatty acids in egg yolk phospholipids upon oxidative damage in HT22 cells

Egg yolk phospholipids are primarily composed of various fatty acids, lysophosphatidylcholine and lysophosphatidylethanolamine. Existing studies have revealed the neuroprotective activity of egg yolk phospholipids. However, it is not clear which digestion products of phospholipids exert neuroprotective activity. The objective of this study was to investigate the neuroprotective effects of different structural components in egg yolk phospholipids based on a DMNQ-induced oxidative damage in HT22 cells. The findings demonstrated that pre-treatment with diverse egg yolk phospholipid components, particularly the polyunsaturated fatty acids, markedly elevated the cell viability and superoxide dismutase activity, diminished the ROS generation, reduced the malondialdehyde levels and elevated the mitochondrial membrane potential. Furthermore, RNA-Seq analysis demonstrated that unsaturated fatty acids exert its neuroprotective effects by upregulating the genes involved in cell proliferation (Jag2 and Ypel3), nervous system development (Ntf5), DNA damage repair (H2ax), and other related processes. These findings provide a theoretical basis for future studies on the characteristic structure of egg yolk phospholipids with profound neuroprotective effects.

Mitochondrial dysfunction as a key player in aggravating periodontitis among diabetic patients: review of the current scope of knowledge

Periodontitis is a prevalent inflammatory disease that leads to significant periodontal tissue destruction and compromised dental health, with its severity exacerbated in individuals with Diabetes Mellitus (DM). This review explores the complex relationship between mitochondrial dysfunction and periodontitis in diabetic patients. Recent studies indicate that the excessive production of reactive oxygen species (ROS), primarily generated by dysfunctional mitochondrial electron transport chain (ETC) complexes, contributes to oxidative stress (OS) and subsequent periodontal tissue damage. The interplay between impaired mitochondrial biogenesis, apoptosis of periodontal cells, and ROS accumulation highlights a critical area of concern in understanding the pathophysiology of diabetic periodontitis. Furthermore, altered glycemic control due to inflammatory processes associated with periodontitis may perpetuate a cyclical detriment to oral and systemic health. This review aims to highlight the mechanistic roles of mitochondrial dysfunction in the aggravation of periodontitis among diabetic patients, emphasizing further research to identify potential therapeutic targets and improve treatment efficacy for this dual pathology.

Nanoparticles induced neurotoxicity

The early development of nanotechnology has spurred major interest on the toxicity of nanoparticles (NPs) due to their ability to penetrate the biological barriers such as the BBB. This review aims at addressing how silver (AgNPs), titanium dioxide (TiO2NPs), zinc oxide (ZnONPs), iron oxide (Fe3O4NPs), carbon NPs, Copper (Cu-NPs), silicon oxide (SiO2 NPs) nanoparticles and quantum dots cause neurotoxicity. Some of the major signaling that occur are the signaling related to oxidative stress, neuroinflammation, mitochondrial dysfunction and cell equilibrium, hence results in neuronal damage and neurodegeneration. It is critical to describe that there are multiple ways by how NPs may be toxic based on their size and surface, dosage, and the recipient's age and health condition. A review on in vitro and in vivo analysis provides information about the toxic potentials of NPs and preventive measures including modification of NP surface and antioxidant treatment. The results underline the necessity of comprehensive safety assessments to allow the further utilization of nanoparticles across the economy.

-hydroxybutyrate enhances brain metabolism in normoglycemia and hyperglycemia, providing cerebroprotection in a mouse stroke model

Hyperglycemia in poorly controlled diabetes is widely recognized as detrimental to organ dysfunction. However, the acute effects of hyperglycemia on brain metabolism and function are not fully understood. The potential protective benefit of ketone bodies on mitochondrial function in the brain has also not been well characterized. Here, we evaluated the acute effects of hyperglycemia and β-hydroxybutyrate (BHB) on brain metabolism by employing a novel approach leveraging adenosine triphosphate (ATP)-dependence of bioluminescence originating from luciferin-luciferase activity. Oxygen consumption rate was measured in ex vivo live brain punches to further evaluate mitochondrial function. Our data demonstrate that brain metabolism in mice is affected by acute exposure to high glucose. This short-term effect of glucose exposure was reduced by co-administration with the ketone body BHB. Additionally, we investigated the functional relevance of BHB using an in vivo photothrombotic stroke model to assess its cerebroprotective effects in presence or absence of acute hyperglycemia. BHB significantly reduced infarct size in the brain stroke model, providing functional evidence for its protective role in the brain. These findings suggest that BHB may effectively mitigate the adverse effects of metabolic stress and ischemic events on brain metabolism and function.

Neuroinflammation and energy metabolism: a dual perspective on ischemic stroke

Ischemic stroke is a prevalent form of cerebrovascular accident, with its pathogenesis involving the intricate interplay between neuroinflammation and energy metabolism. Cerebral ischemia disrupts oxygen and energy supply, triggering metabolic dysregulation and activating neuroinflammatory responses, ultimately resulting in cellular damage. This review provides an exhaustive analysis of the complex mechanisms of ischemic stroke, with a particular focus on the interaction between neuroinflammation and energy metabolism. The interruption of oxygen and energy supply due to cerebral ischemia initiates metabolic dysregulation and activates neuroinflammatory responses, including the release of inflammatory cytokines and the activation of immune cells, contributing to cellular damage and further metabolic disturbances. Studies indicate that dysregulation of energy metabolism significantly impairs neural cell function and interacts with neuroinflammation, exacerbating ischemic brain injury. Therapeutic strategies primarily concentrate on modulating energy metabolism and suppressing neuroinflammatory responses, emphasizing the importance of in-depth research into their interaction to provide a theoretical foundation for new treatment strategies for ischemic stroke. Future research should focus on how to balance anti-inflammatory treatment with energy regulation to minimize neural damage and promote recovery.

Schisandrin B Improves Mitochondrial Function and Inhibits HT22 Cell Apoptosis by Regulating Sirt3 Protein

Neurological diseases refer to pathological changes that occur in the brain, spinal cord, and peripheral nerves. Their etiologies are complex, treatment outcomes are poor, and prognoses are unfavorable. Therefore, how to improve the treatment efficacy of neurological diseases is an urgent problem to be addressed in current clinical practice. Schisandrin B, a commonly used traditional Chinese medicine in clinical settings, has anti-tumor, anti-inflammatory, and wound-healing promoting effects. However, there are relatively few studies on its application in the treatment of neurological diseases. In this study, HT22 nerve cells were cultured, and an injury model was constructed by applying H2O2 stimulation to explore the protective effect of Schisandrin B on these cells. The research results showed that compared with the H2O2 group, Schisandrin B could significantly increase the viability (30.872%) and migration ability (42.756%) of HT22 cells, and inhibit the apoptosis of HT22 cells (22.817%). Further exploration of the mechanism revealed that Schisandrin B regulated the mitochondrial dynamic balance and membrane potential level of HT22 cells by upregulating the expression of Sirt3 protein, enhanced the mitochondrial energy metabolism (with an increase of 53.411% in ATP production), and maintained the integrity of the quantity and structure of mitochondria, ultimately exerting a protective effect on HT22 cells.

Mitochondrial-based therapies for neurodegenerative diseases: a review of the current literature

Neurodegenerative disorders present significant challenges to modern medicine because of their complex etiology, pathogenesis, and progressive nature, which complicate practical treatment approaches. Mitochondrial dysfunction is an important contributor to the pathophysiology of various neurodegenerative illnesses, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). This review paper examines the current literature highlighting the multifaceted functions of mitochondria, including energy production, calcium signaling, apoptosis regulation, mitochondrial biogenesis, mitochondrial dynamics, axonal transport, endoplasmic reticulum-mitochondrial interactions, mitophagy, mitochondrial proteostasis, and their crucial involvement in neuronal health. The literature emphasizes the increasing recognition of mitochondrial dysfunction as a critical factor in the progression of neurodegenerative disorders, marking a shift from traditional symptom management to innovative mitochondrial-based therapies. By discussing mitochondrial mechanisms, including mitochondrial quality control (MQC) processes and the impact of oxidative stress, this review highlights the need for novel therapeutic strategies to restore mitochondrial function, protect neuronal connections and integrity, and slow disease progression. This comprehensive review aims to provide insights into potential interventions that could transform the treatment landscape for neurodegenerative diseases, addressing symptoms and underlying pathophysiological changes.

Mitochondrial Calcium Uniporter knockdown improves the viability of HT22 hippocampal neurons in Alzheimer's disease

Alzheimer's disease (AD) is a degenerative disorder that poses a serious threat because it has no cure. Recently, mitochondrial dysfunction has been shown to directly promote the development of AD. An imbalance in mitochondrial calcium (mCa2+) homeostasis is an important cause of mitochondrial dysfunction. Abnormal expression of mitochondrial calcium uniporter (MCU), a key channel responsible for mCa2+ uptake, can induce an imbalance in mCa2+ homeostasis, ultimately leading to mitochondrial dysfunction. Importantly, we observed a much higher expression level of MCU in the hippocampus of amyloid precursor protein (APP)/presenilin 1 (PS1)/tau transgenic mice than that in the hippocampus of control mice (C57), suggesting that MCU may be a target for the development of treatments for AD. Our recent study revealed the neuroprotective effect of MCU knockdown on hippocampal neurons in APP/PS1/tau mice. In the present study, we used MCU knockdown to investigate the cellular mechanisms involved in amyloid-β (Aβ)1-42 and okadaic acid (OA) cell models of AD. We found that MCU knockdown could increase the survival and decrease the apoptosis of these two cell models by lowering mCa2+ overload, further increasing the mitochondrial membrane potential (MMP) and ultimately reducing the overproduction of reactive oxygen species (ROS). This study showed that MCU knockdown could increase the proliferation and viability of HT22 hippocampal neurons, which might explain the neuroprotective effect of MCU knockdown on AD, potentially leading to the development of novel and effective therapies for AD.

Mitochondria targeted nanoparticles for the treatment of mitochondrial dysfunction-associated brain disorders

Mitochondria play a significant role in several cellular activities and their function in health and disease has become an important area of research. Since the brain is a high-energy-demanding organ, it is particularly vulnerable to mitochondrial dysfunction. This has been implicated in several brain disorders including neurodegenerative, psychiatric and neurological disorders, e.g., Parkinson's disease and schizophrenia. Significant efforts are underway to develop mitochondria-targeting pharmaceutical interventions. However, the complex mitochondrial membrane network restricts the entry of therapeutic compounds into the mitochondrial matrix. Nanoparticles (NPs) present a novel solution to this limitation, while also increasing the stability of the therapeutic moieties and improving their bioavailability. This article provides a detailed overview of studies that have investigated the treatment of mitochondrial dysfunction in brain disorders using either targeted or non-targeted NPs as drug delivery systems. All the NPs showed improved mitochondrial functioning including a reduction in reactive oxygen species (ROS) production, an improvement in overall mitochondrial respiration and a reversal of toxin-induced mitochondrial damage. However, the mitochondrial-targeted NPs showed an advantage over the non-targeted NPs as they were able to improve or rescue mitochondrial dynamics and biogenesis, and they required a lower concentration of the in vivo therapeutic dosage of the drug load to show an effect. Consequently, mitochondria-targeted NPs are a promising therapeutic approach. Future studies should exploit advances in nanotechnology, neuroscience and chemistry to design NPs that can cross the blood-brain barrier and selectively target dysfunctional mitochondria, to improve treatment outcomes.

Molecular Motors in Blood-Brain Barrier Maintenance by Astrocytes

The blood-brain barrier (BBB) comprises distinct cell types, including endothelial cells, pericytes, and astrocytes, and is essential for central nervous system (CNS) homeostasis by selectively regulating molecular transport and maintaining integrity. In particular, astrocytes are essential for BBB function, as they maintain BBB integrity through their end-feet, which form a physical and biochemical interface that enhances endothelial cell function and barrier selectivity. Moreover, they secrete growth factors like vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β), which regulate tight junction (TJ) proteins (e.g., claudins and occludins) crucial for limiting paracellular permeability. Molecular motors like kinesins, dynein, and myosins are essential for these astrocyte functions. By facilitating vesicular trafficking and protein transport, they are essential for various functions, including trafficking of junctional proteins to support BBB integrity, the proper mitochondria localization within astrocyte processes for efficient energy supply, the polarized distribution of aquaporin (AQP)-4 at astrocyte end-feet for regulating water homeostasis across the BBB, and the modulation of neuroinflammatory responses. Moreover, myosin motors modulate actomyosin dynamics to regulate astrocyte process outgrowth, adhesion, migration, and morphology, facilitating their functional roles. Thus, motor protein dysregulation in astrocytes can compromise BBB function and integrity, increasing the risk of neurodegeneration. This review explores the complex interplay between astrocytes and molecular motors in regulating BBB homeostasis, which represents an attractive but poorly explored area of research.

Multifunctional selenium-doped carbon dots for modulating Alzheimer's disease related toxic ions, inhibiting amyloid aggregation and scavenging reactive oxygen species

β-Amyloid (Aβ) protein deposition, oxidative stress, and metal ion imbalance are established pathological features of Alzheimer's disease (AD), highlighting the imperative to efficiently reduce Aβ aggregates formation, alleviate oxidative stress, and chelate metal ions. Existing research indicates the necessity of developing multifunctional nanomaterials to facilitate multi-target therapy. In this work, we designed and prepared multifunctional selenium-doped carbonized polymer dots (SeCDs), and examined the multifunctionality at inhibiting Aβ, cleaning reactive oxygen species (ROS), and modulating copper ions. SeCDs exhibit efficient clearance of active hydroxyl radicals and superoxide anion radicals. In addition, SeCDs can chelate Cu ions, therefore reducing the cytotoxicity linked to the Aβ-Cu complex. More importantly, SeCDs can effectively reduce the level of intracellular reactive oxygen species. This study demonstrates the potential of carbon dots as a multifunctional β-sheet disruptor, while multifunctional SeCDs offer promising avenues for further research in the multi-target treatment of Alzheimer's disease. Meanwhile, this strategy provides a new perspective on the development of zero-dimensional carbon materials in Alzheimer's therapy.

Pharmacological approaches to enhance mitochondrial biogenesis: focus on PGC-1Α, AMPK, and SIRT1 in cellular health

BACKGROUND

Mitochondrial biogenesis is essential for cellular energy balance and metabolic stability. Its dysregulation is linked to various metabolic and neurodegenerative diseases, making it a significant therapeutic target. Pharmacological approaches aimed at enhancing mitochondrial function have gained attention for their potential to restore cellular metabolism.

OBJECTIVES

This review examines recent advancements in pharmacological strategies targeting mitochondrial biogenesis, focusing on the roles of PGC-1α, AMPK, and SIRT1, alongside novel therapeutic agents and drug delivery systems.

METHODS

A systematic review of studies published between 2018 and 2023 was conducted using databases such as PubMed, Web of Science, and Elsevier. Keywords related to mitochondrial biogenesis and pharmacological modulation were used to identify relevant literature.

RESULTS

Various pharmacological agents, including resveratrol, curcumin, and metformin, activate mitochondrial biogenesis through different pathways. SIRT1 activators and AMPK agonists have shown promise in improving mitochondrial function. Advances in mitochondria-targeted drug delivery systems enhance therapeutic efficacy, yet challenges remain in clinical translation due to the complexity of mitochondrial regulation.

CONCLUSION

Pharmacological modulation of mitochondrial biogenesis holds therapeutic potential for metabolic and neurodegenerative diseases. While preclinical studies are promising, further research is needed to optimize drug efficacy, delivery methods, and personalized treatment strategies.

β-Hydroxybutyrate enhances brain metabolism in normoglycemia and hyperglycemia, providing cerebroprotection in a mouse stroke model

Hyperglycemia in poorly controlled diabetes is widely recognized as detrimental to organ dysfunction. However, the acute effects of hyperglycemia on brain metabolism and function are not fully understood. The potential protective benefit of ketone bodies on mitochondrial function in the brain has also not been well characterized. Here, we evaluated the acute effects of hyperglycemia and β-hydroxybutyrate (BHB) on brain metabolism by employing a novel approach leveraging adenosine triphosphate (ATP)-dependence of bioluminescence originating from luciferin-luciferase activity. Oxygen consumption rate was measured in ex vivo live brain punches to further evaluate mitochondrial function. Additionally, we investigated the functional relevance of BHB using an in vivo photothrombotic stroke model to assess its cerebroprotective effects. Our data demonstrate that brain metabolism in mice is affected by acute exposure to high glucose, at a level similar to consuming food or a beverage with high sucrose. This short-term effect of glucose exposure was reduced by co-administration with the ketone body BHB. Moreover, BHB significantly reduced infarct size in the brain stroke model, providing evidence for its functional protective role in the brain. These findings suggest that BHB may effectively mitigate the adverse effects of metabolic stress and ischemic events on brain metabolism and function.

Microvascular Dysfunction, Mitochondrial Reprogramming, and Inflammasome Activation as Critical Regulators of Ischemic Stroke Severity Induced by Chronic Exposure to Prescription Opioids

The opioid epidemic endangers not only public health but also social and economic welfare. Growing clinical evidence indicates that chronic use of prescription opioids may contribute to an elevated risk of ischemic stroke and negatively impact poststroke recovery. In addition, NLRP3 inflammasome activation has been related to several cerebrovascular diseases, including ischemic stroke. Interestingly, an increase in NLRP3 inflammasome activation has also been reported in chronic opioid exposure. Given the pivotal roles of the blood-brain barrier (BBB) and oxidative stress in ischemic stroke pathophysiology, this study focuses on the impact of chronic exposure to prescription opioids on the integrity of cerebrovascular microvasculature, endothelial mitochondrial homeostasis, and the outcomes of ischemic stroke in male wild-type and NLRP3-deficient mice. Our results demonstrate that chronic opioid exposure can compromise the integrity of the BBB and elevate the generation of reactive oxygen species (ROS), resulting in endothelial mitochondrial dysfunction and apoptosis activation. We also provide evidence that opioid exposure enhances inflammasome activation and inflammatory responses and increases the severity of an ischemic stroke. The antioxidant N-acetylcysteine ameliorated these opioid-induced alterations and accelerated the poststroke tissue restoration and functional recovery processes in opioid-exposed mice. Importantly, there was also a significant decrease in ischemic stroke damage in the NLRP3-deficient mice with chronic opioid exposure as compared with wild-type controls. These findings indicate that chronic exposure to prescription opioids impacts the outcome of ischemic stroke by damaging microvascular cerebral integrity through inflammasome activation and mitochondrial dysfunction.

Mapping brain neural networks in stress brain connectivity

Stress can cause severe damage to the CNS and contribute to an increased risk of neurological and psychiatric disorders. Gaining more insight into the neurobiology of stress is essential to treating neurological disorders associated with stress, which account for a high percentage of the world's disease burden. However, because of complicated variations in stressor types, stress perception, and preceding exposure to stressors, studying the impacts of stress is challenging. Gender, age, and timing are other crucial variables that can influence the stress response. Behavioral, physiological, genetic, and cellular/molecular neuroscience methodologies have all been widely applied in various research contexts to examine the neurobiological impacts of stress. Furthermore, because these approaches are invasive and hence undesirable or impractical for use in humans, they are frequently challenging to adapt to a therapeutic context. As an alternative to invasive procedures, functional neuroimaging approaches are starting to be developed. We discuss in this chapter brain neural networks under stress brain connection.

Penehyclidine hydrochloride activates PARK2 and modulates ubiquitination of AIFM1 to rescue renal tubular injury in diabetic kidney disease

BACKGROUND

Renal tubular injury (RTI) is one of the key characteristics of diabetic nephropathy (DN). Penehyclidine hydrochloride (PHC) was an anticholinergic drug with renoprotective effects, but its specific mechanism in the treatment of DN was still unclear.

METHODS

We treated different diabetic mouse models and high glucose-induced RTI models by PHC. Histological analyses were performed using flow cytometry and staining, and ELISA evaluated the ROS, apoptosis, and related markers under different treatments. The molecular interactions were analyzed by ChIP, dual-luciferase reporter, and CoIP.

RESULTS

PHC alleviated RTI by activating mitophagy and inhibiting apoptosis, and the protective effect could be rescued by PARK2 knockdown. Nrf2 bound to the promoter region of PARK2 and promoted its expression. PHC reduced the level of apoptosis by reducing the degree of nuclear translocation of AIFM1, which was rescued by PARK2 knockdown. PARK2 knockdown reduced the non-degradative ubiquitination of AIFM1, thus promoting its nuclear translocation and ultimately facilitating renal tubular cells (RTCs) apoptosis. The over-expression of AIFM1 rescued the RTCs apoptosis antagonized by PHC.

CONCLUSIONS

PHC activated Nrf2 to up-regulate PARK2 transcription to induce mitophagy and inhibit apoptosis mediated by nuclear translocation of AIFM1 through promoting non-degradative ubiquitination of AIFM1, ultimately rescuing RTI in DN.

Mitochondrial transplantation in brain disorders: Achievements, methods, and challenges

Mitochondrial transplantation is a new treatment strategy aimed at repairing cellular damage by introducing healthy mitochondria into injured cells. The approach shows promise in protecting brain function in various neurological disorders such as traumatic brain injury/ischemia, neurodegenerative diseases, cognitive disorders, and cancer. These conditions are often characterized by mitochondrial dysfunction, leading to impaired energy production and neuronal death. The review highlights promising preclinical studies where mitochondrial transplantation has been shown to restore mitochondrial function, reduce inflammation, and improve cognitive and motor functions in several animal models. It also addresses significant challenges that must be overcome before this therapy can be clinically applied. Current efforts to overcome these challenges, including advancements in isolation techniques, cryopreservation methods, finding an appropriate mitochondria source, and potential delivery routes, are discussed. Considering the rising incidence of neurological disorders and the limited effectiveness of current treatments, this review offers a comprehensive overview of the current state of mitochondrial transplantation research and critically assesses the remaining obstacles. It provides valuable insights that could steer future studies and potentially lead to more effective treatments for various brain disorders.

Targeting mitochondrial dynamics: A promising approach for intracerebral hemorrhage therapy

Intracerebral hemorrhage (ICH) is a major global health issue with high mortality and disability rates. Following ICH, the hematoma exerts direct pressure on brain tissue, and blood entering the brain directly damages neurons and the blood-brain barrier. Subsequently, oxidative stress, inflammatory responses, apoptosis, brain edema, excitotoxicity, iron toxicity, and metabolic dysfunction around the hematoma further exacerbate brain tissue damage, leading to secondary brain injury (SBI). Mitochondria, essential for energy production and the regulation of oxidative stress, are damaged after ICH, resulting in impaired ATP production, excessive reactive oxygen species (ROS) generation, and disrupted calcium homeostasis, all of which contribute to SBI. Therefore, a central factor in SBI is mitochondrial dysfunction. Mitochondrial dynamics regulate the shape, size, distribution, and quantity of mitochondria through fusion and fission, both of which are crucial for maintaining their function. Fusion repairs damaged mitochondria and preserves their health, while fission helps mitochondria adapt to cellular stress and removes damaged mitochondria through mitophagy. When this balance is disrupted following ICH, mitochondrial dysfunction worsens, oxidative stress and metabolic failure are exacerbated, ultimately contributing to SBI. Targeting mitochondrial dynamics offers a promising therapeutic approach to restoring mitochondrial function, reducing cellular damage, and improving recovery. This review explores the latest research on modulating mitochondrial dynamics and highlights its potential to enhance outcomes in ICH patients.

Intercellular Tunneling Nanotubes as Natural Biophotonic Conveyors

Tunneling nanotubes (TNTs), submicrometer membranous channels that bridge and connect distant cells, play a pivotal role in intercellular communication. Organelle transfer within TNTs is crucial in regulating cell growth, signal transmission, and disease progression. However, precise control over individual organelle transport within TNTs remains elusive. In this study, we introduce an optical technique that harnesses TNTs as biophotonic conveyors for the directional transport of individual organelles between cells. By utilizing near-infrared light propagating along the TNTs, optical forces were exerted on the organelles, enabling their active transport in a predetermined direction and at a controlled velocity. As a potential application, TNT conveyors were employed to inhibit mitochondrial hijacking from immune cells to cancer cells, thereby activating immune cells and suppressing cancer cell growth. Furthermore, neural modulation was achieved by transporting mitochondria and neurotransmitter-containing vesicles between neurons via TNT conveyors and axonal conveyors, respectively. This study presents a robust and precise approach to immune activation and neural regulation through the manipulation of organelle transfer at the subcellular level.

Targeting uric acid: a promising intervention against oxidative stress and neuroinflammation in neurodegenerative diseases

Oxidative stress and neuroinflammation are recognized as key factors in the development of neurodegenerative diseases, yet effective interventions and biomarkers to address oxidative stress and neuroinflammation in these conditions are limited. Uric acid (UA), traditionally associated with gout, is now gaining prominence as a potential target in neurodegenerative diseases. Soluble UA stands out as one of the most vital antioxidant compounds produced by the human body, accounting for up to 55% of the extracellular capacity to neutralize free radicals. While there is increasing evidence supporting the neuroprotective properties of UA in Parkinson's disease and Alzheimer's disease, gaps in knowledge still exist regarding the underlying mechanisms and how to effectively translate these benefits into clinical practice. Moreover, the current UA elevation therapy exhibits unstable antioxidant properties, individual variability, and even adverse effects, limiting its potential clinical applications. This review consolidates recent advancements in understanding how UA exerts neuroprotective effects on neurodegenerative diseases and emphasizes the dual roles of UA in managing oxidative stress and neuroinflammation. Additionally, the review elucidates the mechanisms through which UA confers neuroprotection. Based on this, the review underscores the significance of UA as a potential biomarker and aims to provide a comprehensive understanding of its potential as a therapeutic target, while also addressing possible challenges to clinical implementation.

Novel Gene Therapy Approaches for Targeting Neurodegenerative Disorders: Focusing on Delivering Neurotrophic Genes

Neurodegenerative illnesses (NDDs) like Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, spinal muscular atrophy, and Huntington's disease have demonstrated considerable potential for gene therapy as a viable therapeutic intervention. NDDs are marked by the decline of neurons, resulting in changes in both behavior and pathology within the body. Strikingly, only symptomatic management is available without a cure for the NDDs. There is an unmet need for a permanent therapeutic approach. Many studies have been going on to target the newer therapeutic molecular targets for NDDs including gene-based therapy. Gene therapy has the potential to provide therapeutic benefits to a large number of patients with NDDs by offering mechanisms including neuroprotection, neuro-restoration, and rectification of pathogenic pathways. Gene therapy is a medical approach that aims to modify the biological characteristics of living cells by controlling the expression of specific genes in certain neurological disorders. Despite being the most complex and well-protected organ in the human body, there is clinical evidence to show that it is possible to specifically target the central nervous system (CNS). This provides hope for the prospective application of gene therapy in treating NDDs in the future. There are several advanced techniques available for using viral or non-viral vectors to deliver the therapeutic gene to the afflicted region. Neurotrophic factors (NTF) in the brain are crucial for the development, differentiation, and survival of neurons in the CNS, making them important in the context of various neurological illnesses. Gene delivery of NTF has the potential to be used as a therapeutic approach for the treatment of neurological problems in the brain. This review primarily focuses on the methodologies employed for delivering the genes of different NTFs to treat neurological disorders. These techniques are currently being explored as a viable therapeutic approach for neurodegenerative diseases. The article exclusively addresses gene delivery approaches and does not cover additional therapy strategies for NDDs. Gene therapy offers a promising alternative treatment for NDDs by stimulating neuronal growth instead of solely relying on symptom relief from drugs and their associated adverse effects. It can serve as a long-lasting and advantageous treatment choice for the management of NDDs. The likelihood of developing NDDs increases with age as a result of neuronal degradation in the brain. Gene therapy is an optimal approach for promoting neuronal growth through the introduction of nerve growth factor genes.

Ghrelin, Neuroinflammation, Oxidative Stress, and Mood Disorders: What Are the Connections?

Ghrelin is a gut peptide hormone associated with feeding behavior and energy homeostasis. Acylated ghrelin binds to the growth hormone secretagogue receptor 1a subtype (GHS-R1a) in the hippocampus, leading to GH release from the anterior pituitary. However, in recent years, ghrelin and its receptor have also been implicated in other processes, including the regulation of cardiomyocyte function, muscle trophism, and bone metabolism. Moreover, GHS-R1a is distributed throughout the brain and is expressed in brain areas that regulate the stress response and emotional behavior. Consistently, a growing body of evidence supports the role of ghrelin in regulating stress response and mood. Stress has consistently been shown to increase ghrelin levels, and despite some inconsistencies, both human and rodent studies suggested antidepressant effects of ghrelin. Nevertheless, the precise mechanism by which ghrelin influences stress response and mood remains largely unknown. Intriguingly, ghrelin and GHS-R1a were consistently reported to exert anti-inflammatory, antioxidant, and neurotrophic effects both in vivo and in vitro, although this has never been directly assessed in relation to psychopathology. In the present review we will discuss available literature linking ghrelin with the stress response and depressive-like behavior in animal models as well as evidence describing the interplay between ghrelin and neuroinflammation/oxidative stress. Although further studies are required to understand the mechanisms involved in the action of ghrelin on mood, we hypothesize that the antiinflammatory and anti-oxidative properties of ghrelin may give a key contribution.

Reactive Oxygen Species, a Potential Therapeutic Target for Vascular Dementia

Vascular dementia (VaD) is a progressive neurodegenerative condition prevalent among elderly adults marked by cognitive decline resulting from injured and/or improperly functioning cerebrovasculature with resultant disruptions in cerebral blood flow. Currently, VaD has no specific therapeutics and the exact pathobiology is still being investigated. VaD has been shown to develop when reactive oxygen species (ROS) form from damaged targets at different levels of organization-mitochondria, endothelial cells, or cerebrovasculature. In this review, we highlight how specific ROS molecules may be important in the development of VaD and how they can be targeted as a potential therapeutic for VaD.

The potential therapeutic strategy in combating neurodegenerative diseases: Focusing on natural products

Neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), Huntington disease (HD), and Multiple sclerosis (MS), pose a significant global health challenge due to their intricate pathology and limited therapeutic interventions. Natural products represent invaluable reservoirs for combating these neurodegenerative diseases by targeting key pathological hallmarks such as protein aggregation, synaptic dysfunction, aberrant proteostasis, cytoskeletal abnormalities, altered energy homeostasis, inflammation, and neuronal cell death. This review provides an in-depth analysis of the mechanisms and therapeutic targets of natural products for their neuroprotective effects. Furthermore, it elucidates the current progress of clinical trials investigating the potential of natural products in delaying neurodegeneration. The objective of this review is to enhance the comprehension of natural products in the prevention and treatment of neurodegenerative diseases, offering new insights and potential avenues for future pharmaceutical research.

Aldehyde dehydrogenase-2 deficiency aggravates neuroinflammation, nociception, and motor impairment in a mouse model of multiple sclerosis

Aldehyde dehydrogenase-2 deficiency (ALDH2∗2) found in 36 % of Han Chinese, affects approximately 8 % of the world population. ALDH2 is a mitochondrial key enzyme in detoxifying reactive aldehydes to less reactive forms. Studies demonstrate a potential link between ALDH2∗2 mutation and neurodegenerative diseases. Multiple sclerosis (MS) is an incurable and disabling neurodegenerative autoimmune disease that induces motor, and cognitive impairment, and hypersensitivity, including chronic pain. Accumulating evidence suggests that reactive aldehydes, such as 4-hydroxynonenal (4-HNE), contribute to MS pathogenesis. Here, using knock-in mice carrying the inactivating point mutation in ALDH2, identical to the mutation found in Han Chinese, we showed that the impairment in ALDH2 activity heightens motor disabilities, and hypernociception induced by experimental autoimmune encephalomyelitis (EAE). The deleterious clinical signs are followed by glial cell activation in the spinal cord and increased 4-HNE levels in the spinal cord and serum. Importantly, the pharmacological ALDH2 activation by Alda-1 ameliorates EAE-induced hypernociception and motor impairment in both wild-type and ALDH2∗2KI mice. Reduced hypernociception was associated with less early growth response protein 1 (EGR1), neuronal and glial activation, and reactive aldehyde accumulation in the spinal cord and serum. Taken together, our data suggest that the mitochondrial enzyme ALDH2 plays a role in regulating clinical, cellular, and molecular responses associated with EAE. This indicates that ALDH2 could serve as a molecular target for MS control, with ALDH2 activators, like Alda-1 as potential neuroprotective candidates. Furthermore, ALDH2∗2 carriers may be at increased risk of developing more accentuated MS symptoms.

A precursor of Aflatoxin B1, Versicolorin A, impairs the mitochondrial function of human intestinal Caco-2 cells

Versicolorin A (VERA) is a mycotoxin produced by Aspergillus section Flavi species that is frequently detected in foodstuffs, particularly in corn. VERA is a precursor of aflatoxin B1 (AFB1), which is currently considered to be the most hazardous mycotoxin. While AFB1 has been shown to impair oxidative phosphorylation (OXPHOS), the impact of VERA on mitochondrial function has not been extensively documented until now. The aim of the present study was to investigate the effect of VERA on mitochondrial function in intestinal Caco-2 cells. To this end, OXPHOS was assessed by measuring the oxygen consumption rate using the Seahorse™ real-time analyzer. In contrast to AFB1, a low concentration of VERA (5 µM) was a strong uncoupler of OXPHOS and inhibited respiratory complexes I and III within a few minutes of exposure. After 24 h of exposure, VERA reduced the transcription of all mitochondrial genes encoding proteins involved in the electron transfer chain as well as decreasing the rate of OXPHOS. This effect was associated with the simultaneous down expression of two genes encoding proteins involved in the initiation phase of mitochondrial DNA transcription: POLRMT and TFB2M. Moreover, VERA induced down expression of genes coding for upstream key glycolytic enzymes, hexokinase and phosphofructokinase. These effects led to a reduced rate of ATP production associated with a cytotoxic effect. Given the significant implications of mitochondrial dysfunction for human health, it is crucial to consider the potential involvement of VERA in mitochondrial diseases.

The Interplay of Mitochondrial Bioenergetics and Dopamine Agonists as an Effective Disease-Modifying Therapy for Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological ailment with a slower rate of advancement that is more common in older adults. The biggest risk factor for PD is getting older, and those over 60 have an exponentially higher incidence of this condition. The failure of the mitochondrial electron chain, changes in the dynamics of the mitochondria, and abnormalities in calcium and ion homeostasis are all symptoms of Parkinson's disease (PD). Increased mitochondrial reactive oxygen species (mROS) and an energy deficit are linked to these alterations. Levodopa (L-DOPA) is a medication that is typically used to treat most PD patients, but because of its negative effects, additional medications have been created utilizing L-DOPA as the parent molecule. Ergot and non-ergot derivatives make up most PD medications. PD is successfully managed with the use of dopamine agonists (DA). To get around the motor issues produced by L-DOPA, these dopamine derivatives can directly excite DA receptors in the postsynaptic membrane. In the past 10 years, two non-ergoline DA with strong binding properties for the dopamine D2 receptor (D2R) and a preference for the dopamine D3 receptor (D3R) subtype, ropinirole, and pramipexole (PPx) have been developed for the treatment of PD. This review covers the most recent research on the efficacy and safety of non-ergot drugs like ropinirole and PPx as supplementary therapy to DOPA for the treatment of PD.

Metabolomics-Based Study of the Protective Effect of 4-Hydroxybenzyl Alcohol on Ischemic Astrocytes

Ischemic stroke is a common and dangerous disease in clinical practice. Astrocytes (ASs) are essential for maintaining the metabolic balance of the affected regions during the disease process. 4-Hydroxybenzyl alcohol (4HBA) from Gastrodia elata Bl. has potential neuroprotective properties due to its ability to cross the blood-brain barrier. In an in vitro experiment, we replicated the oxygen-glucose deprivation/reoxygenation model, and used methyl thiazoly tertrazolium, flow cytometry, kits, and other technical means to clarify the protective effect of 4HBA on primary ASs. In in vivo experiments, the 2VO model was replicated, and immunofluorescence and immunohistochemistry techniques were used to clarify the protective effect of 4HBA on ASs and the maintenance of the blood-brain barrier. Differential metabolites and related pathways were screened and verified using metabolomics analysis and western blot. 4HBA noticeably amplified AS cell survival, reduced mitochondrial dysfunction, and mitigated oxidative stress. It demonstrated a protective effect on ASs in both environments and was instrumental in stabilizing the blood-brain barrier. Metabolomic data indicated that 4HBA regulated nucleic acid and glutathione metabolism, influencing purines, pyrimidines, and amino acids, and it activated the N-methyl-D-aspartate/p-cAMP-response element binding protein/brain-derived neurotrophic factor signaling pathway via N-methyl-D-aspartate R1/N-methyl-D-aspartate 2C receptors. Our findings suggest that 4HBA is a potent neuroprotective agent against ischemic stroke, enhancing AS cell survival and function while stabilizing the blood-brain barrier. The N-methyl-D-aspartate/p-cAMP-response element binding protein/brain-derived neurotrophic factor signaling pathway is activated by 4HBA.

The Interplay of Mitochondrial Dysfunction in Oral Diseases: Recent Updates in Pathogenesis and Therapeutic Implications

Mitochondrial dysfunction is linked to various systemic and localized diseases, including oral diseases like periodontitis, oral cancer, and temporomandibular joint disorders. This paper explores the intricate mechanisms underlying mitochondrial dysfunction in oral pathologies, encompassing oxidative stress, inflammation, and impaired energy metabolism. Furthermore, it elucidates the bidirectional relationship between mitochondrial dysfunction and oral diseases, wherein the compromised mitochondrial function exacerbates disease progression, while oral pathologies, in turn, exacerbate mitochondrial dysfunction. Understanding these intricate interactions offers insights into novel therapeutic strategies targeting mitochondrial function for managing oral diseases. This paper pertains to the mechanisms underlying mitochondrial dysfunction, its implications in various oral pathological and inflammatory conditions, and emerging versatile treatment approaches. It reviews current therapeutic strategies to mitigate mitochondrial dysfunction, including antioxidants, mitochondrial-targeted agents, and metabolic modulators.

Cell life-or-death events in osteoporosis: All roads lead to mitochondrial dynamics

Mitochondria exhibit heterogeneous shapes and networks within and among cell types and tissues, also in normal or osteoporotic bone tissues with complex cell types. This dynamic characteristic is determined by the high plasticity provided by mitochondrial dynamics and is stemmed from responding to the survival and functional requirements of various bone cells in a specific microenvironments. In contrast, mitochondrial dysfunction, induced by dysregulation of mitochondrial dynamics, may act as a trigger of cell death signals, including common apoptosis and other forms of programmed cell death (PCD). These PCD processes consisting of tightly structured cascade gene expression events, can further influence the bone remodeling by facilitating the death of various bone cells. Mitochondrial dynamics, therefore, drive the bone cells to stand at the crossroads of life and death by integrating external signals and altering metabolism, shape, and signal-response properties of mitochondria. This implies that targeting mitochondrial dynamics displays significant potential in treatment of osteoporosis. Considerable effort has been made in osteoporosis to emphasize the parallel roles of mitochondria in regulating energy metabolism, calcium signal transduction, oxidative stress, inflammation, and cell death. However, the emerging field of mitochondrial dynamics-related PCD is not well understood. Herein, to bridge the gap, we outline the latest knowledge on mitochondrial dynamics regulating bone cell life or death during normal bone remodeling and osteoporosis.

Excitotoxicity, Oxytosis/Ferroptosis, and Neurodegeneration: Emerging Insights into Mitochondrial Mechanisms

Mitochondrial dysfunction plays a pivotal role in the development of age-related diseases, particularly neurodegenerative disorders. The etiology of mitochondrial dysfunction involves a multitude of factors that remain elusive. This review centers on elucidating the role(s) of excitotoxicity, oxytosis/ferroptosis and neurodegeneration within the context of mitochondrial bioenergetics, biogenesis, mitophagy and oxidative stress and explores their intricate interplay in the pathogenesis of neurodegenerative diseases. The effective coordination of mitochondrial turnover processes, notably mitophagy and biogenesis, is assumed to be critically important for cellular resilience and longevity. However, the age-associated decrease in mitophagy impedes the elimination of dysfunctional mitochondria, consequently impairing mitochondrial biogenesis. This deleterious cascade results in the accumulation of damaged mitochondria and deterioration of cellular functions. Both excitotoxicity and oxytosis/ferroptosis have been demonstrated to contribute significantly to the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's Disease (HD), Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS). Excitotoxicity, characterized by excessive glutamate signaling, initiates a cascade of events involving calcium dysregulation, energy depletion, and oxidative stress and is intricately linked to mitochondrial dysfunction. Furthermore, emerging concepts surrounding oxytosis/ferroptosis underscore the importance of iron-dependent lipid peroxidation and mitochondrial engagement in the pathogenesis of neurodegeneration. This review not only discusses the individual contributions of excitotoxicity and ferroptosis but also emphasizes their convergence with mitochondrial dysfunction, a key driver of neurodegenerative diseases. Understanding the intricate crosstalk between excitotoxicity, oxytosis/ferroptosis, and mitochondrial dysfunction holds potential to pave the way for mitochondrion-targeted therapeutic strategies. Such strategies, with a focus on bioenergetics, biogenesis, mitophagy, and oxidative stress, emerge as promising avenues for therapeutic intervention.

Leigh has no Brakes: Impaired Inhibition in a Mouse Model of Leigh Syndrome Leads to Enhanced Seizure Sensitivity

Elevated Susceptibility to Exogenous Seizure Triggers and Impaired Interneuron Excitability in a Mouse Model of Leigh Syndrome Epilepsy Manning A, Han V, Stephens A, Wang R, Bush N, Bard M, Ramirez JM, and Kalume F. Neurobiol Dis . 2023;187:106288 Mutations in the nicotinamide adenine dinucleotide dehydrogenase (ubiquinone reductase) iron-sulfur protein 4 (NDUFS4 ) gene, which encodes for a key structural subunit of the OXFOS complex I, lead to the most common form of mitochondrial disease in children known as Leigh syndrome (LS). As in other mitochondrial diseases, epileptic seizures constitute one of the most significant clinical features of LS. These seizures are often very difficult to treat and are a sign of poor disease prognosis. Mice with whole-body Ndufs4 KO are a well-validated model of LS; they exhibit epilepsy and several other clinical features of LS. We have previously shown that mice with Ndufs4 KO in only GABAergic interneurons (Gad2-Ndufs4 -KO) reproduce the severe epilepsy phenotype observed in the global KO mice. This observation indicated that these mice represent an excellent model of LS epilepsy isolated from other clinical manifestations of the disease. To further characterize this epilepsy phenotype, we investigated seizure susceptibility to selected exogenous seizure triggers in Gad2-Ndufs4 -KO mice. Then, using electrophysiology, imaging, and immunohistochemistry, we studied the cellular, physiological, and neuroanatomical consequences of Ndufs4 KO in GABAergic interneurons. Homozygous KO of Ndufs4 in GABAergic interneurons leads to a prominent susceptibility to exogenous seizure triggers, impaired interneuron excitability, and interneuron loss. Finally, we found that the hippocampus and cortex participate in the generation of seizure activity in Gad2- Ndufs4 -KO mice. These findings further define the LS epilepsy phenotype and provide important insights into the cellular mechanisms underlying epilepsy in LS and other mitochondrial diseases.

Synaptic modulation by coffee compounds: Insights into neural plasticity

The physiological structure and functioning of the brain are determined by activity-dependent processes and affected by "synapse plasticity." Because chemical transmitters target and regulate synapses, exogenous chemical stimulants and transmitters can alter their physiological functions by interacting with synaptic surface receptors or chemical modulators. Caffeine, a commonly used pharmacologic substance, can target and alter synapses. It impact various biological, chemical, and metabolic processes related to synaptic function. This chapter investigates how caffeine affects fluctuations in structure and function in the hippocampus formation and neocortical structure, regions known for their high synaptic plasticity profile. Specifically, caffeine modulates various synaptic receptors and channel activities by mobilizing intracellular calcium, inhibiting phosphodiesterase, and blocking adenosine and GABA cellular receptors. These caffeine-induced pathways and functions allow neurons to generate plastic modulations in synaptic actions such as efficient and morphological transmission. Moreover, at a network level, caffeine can stimulate neural oscillators in the cortex, resulting in repetitive signals that strengthen long-range communication between cortical areas reliant on N-methyl-d-aspartate receptors. This suggests that caffeine could facilitate the reorganization of cortical network functions through its effects on synaptic mobilization.

Emerging Multi-omic Approaches to the Molecular Diagnosis of Mitochondrial Disease and Available Strategies for Treatment and Prevention

Mitochondria are semi-autonomous organelles present in several copies within most cells in the human body that are controlled by the precise collaboration of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) encoding mitochondrial proteins. They play important roles in numerous metabolic pathways, such as the synthesis of adenosine triphosphate (ATP), the predominant energy substrate of the cell generated through oxidative phosphorylation (OXPHOS), intracellular calcium homeostasis, metabolite biosynthesis, aging, cell cycles, and so forth. Previous studies revealed that dysfunction of these multi-functional organelles, which may arise due to mutations in either the nuclear or mitochondrial genome, leads to a diverse group of clinically and genetically heterogeneous disorders. These diseases include neurodegenerative and metabolic disorders as well as cardiac and skeletal myopathies in both adults and newborns. The plethora of phenotypes and defects displayed leads to challenges in the diagnosis and treatment of mitochondrial diseases. In this regard, the related literature proposed several diagnostic options, such as high throughput mitochondrial genomics and omics technologies, as well as numerous therapeutic options, such as pharmacological approaches, manipulating the mitochondrial genome, increasing the mitochondria content of the affected cells, and recently mitochondrial diseases transmission prevention. Therefore, the present article attempted to review the latest advances and challenges in diagnostic and therapeutic options for mitochondrial diseases.

Research progress on the relationship between epilepsy and circRNA

OBJECTIVE

This review aims to provide a comprehensive summary of the latest research progress regarding the relationship between epilepsy and circular RNA (circRNA).

METHODS

Relevant literature from the PubMed database was meticulously searched and reviewed. The selected articles focused on investigating the association between epilepsy and circRNA, including studies on expression patterns, diagnostic markers, therapeutic targets, and functional mechanisms.

RESULTS

Epilepsy, characterized by recurrent seizures, is a neurological disorder. Numerous studies have demonstrated significant alterations in the expression profiles of circRNA in epileptic brain tissues, animal models, and peripheral blood samples. These differential expressions of circRNA are believed to be closely linked with the occurrence and development of epilepsy. Moreover, circRNA has shown promising potential as diagnostic markers for epilepsy, as well as prognostic indicators for predicting disease outcomes. Furthermore, circRNA has emerged as a potential therapeutic target for epilepsy treatment, offering prospects for gene therapy interventions.

CONCLUSION

The dysregulation of circRNA expression in epilepsy suggests its potential involvement in the pathogenesis and progression of this disorder. Identifying specific circRNA molecules associated with epilepsy may pave the way for novel diagnostic approaches and therapeutic strategies. However, further investigations are imperative to elucidate the precise functional mechanisms of circRNA in epilepsy and validate its clinical utility.

The role of the "gut microbiota-mitochondria" crosstalk in the pathogenesis of multiple sclerosis

Multiple Sclerosis (MS) is a neurologic autoimmune disease whose exact pathophysiologic mechanisms remain to be elucidated. Recent studies have shown that the onset and progression of MS are associated with dysbiosis of the gut microbiota. Similarly, a large body of evidence suggests that mitochondrial dysfunction may also have a significant impact on the development of MS. Endosymbiotic theory has found that human mitochondria are microbial in origin and share similar biological characteristics with the gut microbiota. Therefore, gut microbiota and mitochondrial function crosstalk are relevant in the development of MS. However, the relationship between gut microbiota and mitochondrial function in the development of MS is not fully understood. Therefore, by synthesizing previous relevant literature, this paper focuses on the changes in gut microbiota and metabolite composition in the development of MS and the possible mechanisms of the crosstalk between gut microbiota and mitochondrial function in the progression of MS, to provide new therapeutic approaches for the prevention or reduction of MS based on this crosstalk.

Is there a biochemical basis for purinergic P2X3 and P2X4 receptor antagonists to be considered as anti-seizure medications?

Patients with epilepsy require improved medications. Purinergic receptors were identified as late as 1976 and are slowly emerging as potential drug targets for the discovery of antiseizure medications. While compounds interacting with these receptors have been approved for use as medicines (e.g., gefapixant for cough) and continue to be explored for a number of diseases (e.g., pain, cancer), there have been no purinergic receptor antagonists that have been advanced for epilepsy. There are very few studies on the channel conducting receptors, P2X3 and P2X4, that suggest their possible role in seizure generation or control. However, the limited data available provides some compelling reasons to believe that they could be valuable antiseizure medication drug targets. The data implicating P2X3 and P2X4 receptors in epilepsy includes the role played by ATP in neuronal excitability and seizures, receptor localization, increased receptor expression in epileptic brain, the involvement of these receptors in seizure-associated inflammation, crosstalk between these purinergic receptors and neuronal processes involved in seizures (GABAergic and glutamatergic neurotransmission), and the significant attenuation of seizures and seizure-like activity with P2X receptor blockade. The discovery of new and selective antagonists for P2X3 and P2X4 receptors is ongoing, armed with new structural data to guide rational design. The availability of safe, brain-penetrant compounds will likely encourage the clinical exploration of epilepsy as a disease entity.

Role of the SARS-CoV-2 Virus in Brain Cells

COVID-19, caused by the SARS-CoV-2 virus, can have neurological effects, including cognitive symptoms like brain fog and memory problems. Research on the neurological effects of COVID-19 is ongoing, and factors such as inflammation, disrupted blood flow, and damage to blood vessels may contribute to cognitive symptoms. Notably, some authors and existing evidence suggest that the SARS-CoV-2 virus can enter the central nervous system through different routes, including the olfactory nerve and the bloodstream. COVID-19 infection has been associated with neurological symptoms such as altered consciousness, headaches, dizziness, and mental disorders. The exact mechanisms and impact on memory formation and brain shrinkage are still being studied. This review will focus on pathways such as the olfactory nerve and blood-brain barrier disruption, and it will then highlight the interactions of the virus with different cell types in the brain, namely neurons, astrocytes, oligodendrocytes, and microglia.

A review of the mechanisms of abnormal ceramide metabolism in type 2 diabetes mellitus, Alzheimer's disease, and their co-morbidities

The global prevalence of type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) is rapidly increasing, revealing a strong association between these two diseases. Currently, there are no curative medication available for the comorbidity of T2DM and AD. Ceramides are structural components of cell membrane lipids and act as signal molecules regulating cell homeostasis. Their synthesis and degradation play crucial roles in maintaining metabolic balance in vivo, serving as important mediators in the development of neurodegenerative and metabolic disorders. Abnormal ceramide metabolism disrupts intracellular signaling, induces oxidative stress, activates inflammatory factors, and impacts glucose and lipid homeostasis in metabolism-related tissues like the liver, skeletal muscle, and adipose tissue, driving the occurrence and progression of T2DM. The connection between changes in ceramide levels in the brain, amyloid β accumulation, and tau hyper-phosphorylation is evident. Additionally, ceramide regulates cell survival and apoptosis through related signaling pathways, actively participating in the occurrence and progression of AD. Regulatory enzymes, their metabolites, and signaling pathways impact core pathological molecular mechanisms shared by T2DM and AD, such as insulin resistance and inflammatory response. Consequently, regulating ceramide metabolism may become a potential therapeutic target and intervention for the comorbidity of T2DM and AD. The paper comprehensively summarizes and discusses the role of ceramide and its metabolites in the pathogenesis of T2DM and AD, as well as the latest progress in the treatment of T2DM with AD.

Mitochondria in Alzheimer's Disease Pathogenesis

Alzheimer's disease (AD) is a progressive and incurable neurodegenerative disorder that primarily affects persons aged 65 years and above. It causes dementia with memory loss and deterioration in thinking and language skills. AD is characterized by specific pathology resulting from the accumulation in the brain of extracellular plaques of amyloid-β and intracellular tangles of phosphorylated tau. The importance of mitochondrial dysfunction in AD pathogenesis, while previously underrecognized, is now more and more appreciated. Mitochondria are an essential organelle involved in cellular bioenergetics and signaling pathways. Mitochondrial processes crucial for synaptic activity such as mitophagy, mitochondrial trafficking, mitochondrial fission, and mitochondrial fusion are dysregulated in the AD brain. Excess fission and fragmentation yield mitochondria with low energy production. Reduced glucose metabolism is also observed in the AD brain with a hypometabolic state, particularly in the temporo-parietal brain regions. This review addresses the multiple ways in which abnormal mitochondrial structure and function contribute to AD. Disruption of the electron transport chain and ATP production are particularly neurotoxic because brain cells have disproportionately high energy demands. In addition, oxidative stress, which is extremely damaging to nerve cells, rises dramatically with mitochondrial dyshomeostasis. Restoring mitochondrial health may be a viable approach to AD treatment.

[Low-level laser therapy in multiple sclerosis: justification and optimization methods of application. (Literature review)]

Multiple sclerosis (MS) is a chronic demyelinating disease that is based on a complex of autoimmune inflammatory and neurodegenerative processes leading to multiple focal and diffuse damage of central nervous system. Treatment of MS causes great difficulties.

OBJECTIVE

To analyze scientific data on the effectiveness and optimization of applying low-level laser therapy methods in patients with MS.

MATERIAL AND METHODS

Databases and libraries, namely PubMed, Scopus, ResearchGate, Google Scholar, J-STAGE, eLibrary.ru, were used for search. Publications of interest towards analysis of the ways of optimization of low-level laser therapy techniques and its effectiveness improvement, prospects for the development of this treatment method were selected. The total number of publications equal 87, mostly in English and Russian, was found.

RESULTS

It was demonstrated, that low-level laser therapy can be considered a promising method of MS treatment. Mechanisms of therapeutic action of low-intensity laser radiation were shown, as well as the results of several clinical studies were presented.

CONCLUSION

It was concluded that optimal values of all technique's indicators, namely wavelength, operation mode, power, frequency, exposure, etc., should be used. Laser blood irradiation (intravenous or external) and laser acupuncture, systemic techniques of low-level laser therapy are obligatory carried out with local irradiation of lesions.